Bag closure with unravel preventing means



March 19, 1963 R. J. WILLIAMS ETAL 3, ,929

BAG CLOSURE WITH UNRAVEL PREVENTING MEANS Filed Aug. 5, 1957 1 FIG. I.

M AN

United States Patent 3,081,929 BAG CLOSURE WITH UNRAVEL PREVENTING MEANSRussell J. Williams, Clayton, and Charles V. Brady, St. Louis, Mo.,assignors to Bemis Bro. Bag Company, St. Louis, Mo., a corporation ofMissouri Filed Aug. 5, 1957, Ser. No. 676,250 9 Claims. (Cl. 229-63)This invention relates to bags, and more particularly to unravelablestitch type closures for bags.

Among the several objects of the invention may be noted the provision ofunravelable stitch type closure constructions for bags, and particularlyfor multiwall paper bags, which may be easily unraveled to open the bagwithout the use of any tools, and which are practical and virtuallyfoolproof; the provision of closures of this character which, whilebeing easily opened when desired, are strong closures, adapted towithstand strains resulting from dropping or other rough handling of thebags; the provision of closures of this character adapted for unravelingof the entire line of stitching in one piece with assurance that therewill not be any thread particles that may contaminate the contents ofthe bag; and the provision of closures of this character which areeconomical in respect to manufacture. Other objects and features will bein part apparent and in part pointed out hereinafter.

The invention accordingly comprises the constructions hereinafterdescribed, the scope of the invention being indicated in the followingclaims.

In the accompanying drawings, in which several of various possible.embodiments of the invention are illustrated, FIG. 1 is a view inelevation ofone end of a bag having a closure of this invention;

FIG. 2 is an enlarged plan view of the upper right corner of the bagshown in FIG. 1;

' FIG. 3 is a view in elevation of the upper right corner of the bagshown in FIG. 1, illustrating the initial step in the opening of thebag;

FIG. 4 is a view similar to FIG. 1 illustrating a modification;

FIG. 5 is a view in elevation of the upper right corner of the bag shownin FIG. 4 illustrating the initial step in the opening of the bag;

FIG. 6 is a greatly enlarged cross section taken on line 6-6 of FIG. 1or FIG. 4;

FIG. 7 is a view in elevation of a corner of a bag showing anotherpossible modification; and,

FIG. 8 is a view in elevation of a corner of a bag showing still anotherpossible modification.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawings.

Referring to FIGS. 1 and 2 of the drawings, a multiwall paper bag havingan end closure of this invention is indicated at 1. For simplicity, thebag is shown as a two-ply bag, the inner ply being designated 3 and theouter ply 5. It will be understood that a multiwall bag usually willhave more than two plies. As shown, the bag is a gusseted bag, thegussets being indicated at 7. The closure includes a paper tape 9 foldedaround the end of the bag. The tape may or may not be pasted to the bag.If it is pasted to the bag, the paste is applied along its side marginsin narrow stripes. A line of stitching indicated at 11 is driven throughthe tape and through the walls of the bag securing together the wallsadjacent the end of the bag. When the tape has its margins pasted to thebag by narrow stripes of paste, the line of stitching is located outwardof the stripes of paste. The

' length of the tape 9 is greater than the width of the bag,

and the tape has end portions 13 and 15 which extend past the side edgesof the bag. The stitching 11 extends completely throughout the length ofthe tape and, as shown, may be driven through a narrow paper ribbon 17located on the side of the bag which is referred to as the needle side,this side being the side which faced the needle of the sewing machineemployed for stitching.

In accordance with this invention, the stitching at 11 is of a singlethread readily unravelable chain stitch type. As illustrated in FIG. 6,the single thread used for this stitching is designated 19. As will beunderstood by those conversant with the art, the stitching is formed byfeeding the bag with the tape 9 folded around the end of the bag througha sewing machine having a needle which drives loops 21 of the thread 19through the bag, thereby forming needle holes 23 in the bag, the loopsextending from the needle side of the tape 9 through the needle holes tothe other side of the tape, each loop being laid over on the said otherside and extending through the preceding loop 21. This type of stitchingis unraveled with ease by taking hold of that end of the thread which isat the trailing end of the stitching in relation to the passage of thebag through the sewing machine, this being the end of the thread at thatend of the stitching in the direction in which the loops are laid over(the right .end of the stitching as illustrated in FIGS. 1 and 6 of thedrawings herein). It will be understood that unraveling proceeds bysuccessively pulling out the loops 21, the pulling out of each loopfreeing the next loop so that it may be pulled out.

Further in accordance with this invention, the stitching 11 is anchoredagainst unraveling at a point between that end of the tape 9 from whichunraveling: progresses (its right end as viewed in the drawings) and theadjacent side edge of the bag (the right side edge of the bag). As

r shown in FIGS. 1 and 2, this anchoring is effected by folding the endportion 15 of the tape which projects which is located somewhat outwardfrom the side edge of the bag. The end portion 15 is folded over on theneedle side of the bag. The adhesive 25 is preferably located inwardfrom the very end of the end portion of the tape so that the very end ofthe tape may be readily grasped to rip the folded-over portion 15 awayfrom the bag when it is desired to open the bag, and also to leave ashort portion of the stitching which lies outward of the adhesive and isfree of adhesive for easy grasping.

With the end portion 15 of the tape 9 folded back and adhered to the bagas above described, and hence with the end portion of the stitching fromwhich unraveling progresses folded back with the tape and anchored tothe bag, unraveling of the stitching such as might occur in the absenceof any anchoring thereof is prevented even under severe strains such asmay occur due to dropping or other rough handling of the bag. It will beobserved that the thread is anchored to the tape at a point outward ofthe side edge of the bag, which means that the anchor is not subject tosevere strains which, when the bag is dropped, come on the portion ofthe stitching which extends from one side edge of the bag to the other.With the anchor so located it is also insured that there will be nounraveling whatsoever of the stitching inward past the side edge of thebag such as would open up the bag and cause loss of its contents.

To open the bag shown in FIGS. 1 and 2, all that needs be done is totake hold of the folded-over end portion 15 of the tape 9 and pull itaway from the bag so that it extends laterally outward free of the bagas illustrated in FIG. 3, then to take hold of the end of the thread on3 the needle side of the bag and pull it. The thread will readily pullout of the adhesive 25 on the tape and then may be quickly unraveled andpulled out of the bag as one continuous length of thread without anypossibility of loose bits or pieces of thread contaminating the contentsof the bag, as is desirable for certain products, in particular foodproducts for human consumption and animal feed. It will be understoodthat suitable instructions as to the pulling of the end of the tape andthe pulling of the end of the thread may be printed on the bag.

FIG. 4 illustrates a modification which is in all respects the same asthat of FIGS. 1 and 2 except that the end portion 15 of the tape,instead of being folded back on a line parallel to the side of the bag,is folded back on a line 29 angled outward at a 45 angle in thedirection away from the end of the bag. FIG. 5 illustrates the endportion of the tape of the FIG. 4 bag as it appears when pulled free ofthe bag and made to extend laterally outward.

FIG. 7 illustrates another possible modification in which the endportion 15 of the tape is not folded back, being left to extendlaterally outward from the side edge of the bag, and in which thestitching is anchored by means of a spot of adhesive 31 applied to thetape outward of the side edge of the bag and inward of the end of thetape. To open the bag in this case, it is simply necessary to grasp andpull the end of the thread.

FIG. 8 illustrates another possible modification similar to FIG. 7except that instead of using a spot of paste for anchoring thestitching, there is used a staple 33 driven through the tape from theneedle side and clinched around the stitching outward of the side edgeof the bag and inward of the end of the tape. To open the bag in thiscase, the end of the thread may be pulled to pull the thread through thestaple and release the thread loops to the left of the staple.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

As various changes could be made in the above constructions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

We claim:

1. A bag having a member extending out from one side edge at one endthereof, a line of stitching driven through the walls of the bag andthrough said member and securing the walls together adjacent said end ofthe bag, the stitching being of a single-thread readily unravelablechain stitch type as to which unraveling progresses from one endthereof, the stitching extending to the outer end of said member andbeing unravelable from its end at the outer end of said member, andmeans releasably securing the thread to said member at a point betweenthe outer end of said member and said side edge of the bag, the portionof the thread from said one end of the thread to said point being freeto be released from said member, said means anchoring the thread againstunraveling beyond said point until said portion of the thread isreleased and pulled to disengage the thread from said memher at saidpoint, continued pulling of the thread resulting in unraveling thereofacross the bag.

2. A bag as set forth in claim 1 wherein said means comprises adhesive.

3. A bag having an end closure constituted by a tape folded around therespective end of the bag and a line of stitching driven through thetape and through the walls of the bag and securing the walls togetheradjacent said end of the bag, the stitching being of a single-threadreadily unravelable chain stitch type as to which unraveling proressesfrom one end thereof, the length of the tape being greater than thewidth of the bag and the tape having an extension beyond one side edgeof the bag, the stitching extending to and terminating at the end ofsaid extension of the tape and being unravelable from its end at the endof said extension of the tape, and means releasably securing the threadto the extension of the tape at a point between said end of theextension and said side edge of the bag, the portion of the thread fromsaid end of the thread to said point being free to be released from thetape, said means anchoring the thread against unraveling beyond saidpoint until said portion of the thread is released and pulled todisengage the thread from the tape at said point, continued pulling ofthe thread resulting in unraveling thereof across the bag.

4. A bag as set forth in claim 3 wherein said means comprises adhesive.

5. A bag as set forth in claim 3 wherein said extension is folded backon the bag and said means comprises adhesive securing said folded-backextension to the bag.

6. A bag as set forth in claim 5 wherein said extension is folded backon a line generally parallel to the side edge of the bag.

7. A bag as set forth in claim 5 wherein said extension is folded backon a line which is angled outward in the direction away from the end ofthe bag.

8. A bag as set forth in claim 3 wherein said extension is free of thebag and said means comprises a spot of adhesive applied to the threadand the extension.

9. A bag as set forth in claim 3 wherein said extension is free of thebag and said means comprises a staple driven through said extension andclinched around the stitching.

References Cited in the file of this patent UNITED STATES PATENTS

1. A BAG HAVING A MEMBER EXTENDING OUT FROM ONE SIDE EDGE AT ONE ENDTHEREOF, A LINE OF STITCHING DRIVEN THROUGH THE WALLS OF THE BAG ANDTHROUGH SAID MEMBER AND SECURING THE WALLS TOGETHER ADJACENT SAID END OFTHE BAG, THE STITCHING BEING OF A SINGLE-THREAD READILY UNRAVELABLECHAIN STITCH TYPE AS TO WHICH UNRAVELING PROGRESS FROM ONE END THEREOF,THE STITCHING EXTENDING TO THE OUTER END OF SAID MEMBER AND BEINGUNRAVELABLE FROM ITS END AT THE OUTER END OF SAID MEMBER, AND MEANSRELEASABLY SECURING THE THREAD TO SAID MEMBER AT A POINT BETWEEN THEOUTER END OF SAID MEMBER AND SAID SIDE EDGE OF THE BAG, THE PORTION OFTHE THREAD FROM SAID ONE END OF THE THREAD TO SAID POINT BEING FREE TOBE RELEASED FROM SAID MEMBER, SAID MEANS ANCHORING THE THREAD AGAINSTUNRAVELING BEYOND SAID POINT UNTIL SAID PORTION OF THE THREAD ISRELEASED AND PULLED TO DISENGAGE THE THREAD FROM SAID MEMBER AT SAIDPOINT, CONTINUED PULLING OF THE THREAD RESULTING IN UNRAVELING THEREOFACROSS THE BAG.